Method of completing a well using a completion and kill valve

ABSTRACT

A completion and kill valve adapted to be placed immediately above a packer in the well production tubing including a tubular member having an inner bore and a circulation channel therein permitting communication between the inner bore and the well annulus area adjacent the exterior of the tubular member. A movable sleeve closes or opens communication through the circulation channel in response to various pressures and a spring bias acting on the sleeve. Provisions for locking the sleeve in the open position and subsequently unlocking the sleeve in response to inner bore pressure are provided.

United States Patent 1191 Mott t v July 16, 1974 METHOD OF COMPLETING AWELL 3,130,782 4/1964 Rike 166/313 USING A COMPLETION AND KILL VALVE3,306,365 2/1967 Kammerer, Jr.. 166/154 3,338,311 8/1967 Conrad 166/154[75] Inventor: James D. Mott, Houston, Tex;

A ignee: Company Primary Examiner-James Filed: Mar- 3 Attorney, Agent,or Firm-Pravel, Wilson & Matthews [21] Appl. No.: 344,602 [57] ABSTRACTRelated US. Application Data A completion and kill valve adapted to beplacedim- [62] Division of S61. NO. 138,947, April 30, 1971, Pat.lnecllately fibove Packer the prodllcmn No. 317507752 mg mcludmg atubular member having an nner bore and a circulation channel thereinpermitting commu- 52 US. Cl. 166/313, 166/315 nieatioh between the innerbore and the annulus 51 1111.01 12211141/00 area adjacent the exteriorof the tubular member- A [58] Fieldof Search 166/313, 314, 315', 154,movable Sleeve Closes or Opens communication 224 R through thecirculation channel in response to various pressures and a spring biasacting on the sleeve. Provi- 5 References Cited sions for locking thesleeve in the open position and UNITED STATES PATENTS subsequentlyunlocking the sleeve in response to inner I bore pressure are provided.2,649,915 8/1953 Mlller l66/244R 3,115,187 12/1963 Brown...-. 166/313 24Claims, 9 Drawing Figures I: v /2a /0 7 PATENTEBJUL 1 61914 823.7 7 8sum 2 or 5 PAIENTEU JUL 1 6 I974 SHEEI a 0F, 5

METHOD OF COMPLETING A WELL USING A COMPLETION AND KILL VALVE CROSSREFERENCE TO RELATED APPLICATIONS This is a division of application Ser.No. 138,947,

I filed Apr. 30, 1971, and now US. Pat. No. 3,750,752

issued Apr. 7, 1973.

BACKGROUND OF THE INVENTION The invention relates to the field of acompletion and kill valve.

One of the problems in completing a well has been removing heavydrilling mud from the production tubing to allow hydrocarbons within aformation to flow into the production tubing and on to the surface. Aprior approach has been to use a swabbing tool in the production tubingto draw the drilling mud to the surface. Swabbing was costly, timeconsuming and dangerous. For example the drilling fluid brought to thesurface made the working area slippery and unpleasant. Nitrogeninjection has also been used to complete a well by lowering the densityof the drilling mud in the production tubing and allowing thehydrocarbon pressure to overcome the hydrostatic head of drilling fluid.This method was also costly and time consuming as well as requiringspecial services and equipment.

Othe devices to complete a well have permitted circulation of a lightfluid down the production tubing with the heavy drilling fluid returningup the annulus, but these devices have required that hazardous wireline, packer or tubing work be done'under pressure in either opening orclosing the device.

Prior art attempts to kill a well by filling the production tubing withdrilling fluid back circulated from the annulus into the tubing havealso entailed wire line work under pressure or moving the well head orpacker with formation pressure on the tubing in either opening orclosing the device.

SUMMARY OF THE INVENTION in addition to differential pressures acting onvarious portions of the movable member to close and open the circulationchannel to communication therethrough. A movable, releasable latchmember moves to a locking position in response to inner bore pressurecommunicated through a locking channel for fastening the movable memberor sleeve in the open position and moves to a free position in responseto inner bore pressure communicated through a sensing channel forreleasing the sleeve to thereby enable the sleeve to return to pressureresponsive operation.

An object of the present invention is to provide a new and improvedcompletion and kill valve for tubing;

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of thecompletion and kill valve of the present invention positioned in asingle completion well production tubing;

FIG. 2 is a perspective view of the completion and kill valve positionedin a dual completion well production tubing;

FIG. 3 is a perspective view of the employment of a plurality ofcompletion and kill valves in a multiple, for example, triple completionwell production tubing;

FIG. 4 is a partial cross-sectional view of the completion and killvalve of the present invention;

FIG. 5 is a view similar to FIG. 2, illustrating the valve of thepresent invention maintained closed by outer pressure;

FIG. 6 is a view similar to FIG. 4, illustrating the valve of thepresent invention in the open position;

FIG. 7 is a view similar to FIG. 6, illustrating the valve of thepresent invention in the locked open position.

FIG. 8 is a view similar to FIG. 7, illustrating the valve of thepresent invention in the locked open position prior to unlocking;

FIG. 9 is a view similar to FIG. 4, illustrating another embodiment ofthe present invention.

' I DESCRIPTION OF THE PREFERRED EMBODIMENT As illustrated in FIGS. 1, 2and 3, the completion and kill valve of the present invention isgenerally illustrated by the numeral 10 and is connected in a tubularproduction string or conduit T above a packer P as is well known in theart. The production string T is positioned in a well casing 11 locatedin a subsurface formation F for recovery of hydrocarbons within theformation F through perforations O, as is well known in v the art.

As illustrated in FIG. 4, the completion and kill valve 10 isillustrated in more detail and includes a tubular member 15 which isconnected through the usual box and pin threaded connection 16 and 17,with the production string T.

The tubular member 15 is provided with an inner bore or channel 20 whichcommunicates with the inner bore or channel 21 of the production tubingT. The inner bore 20 of the tubular member 15 includes a larger diameterupper portion 20a, a shoulder 20b and a smaller diamter portion 200.

A circulation channel 25 is formed through the wall of tubular member 15above the shoulder 20b for permitting communication between the innerbore 20 and the area adjacent the exterior of tubular member 15.

A movable member 30 is mounted with the tubular member 15 and adapted tobe slidably positioned in an open position, illustrated in FIGS. 6, 7and 8, permit ting flow through the circulation channel 25 and a closedposition, illustrated in FIGS. 4 and 5, blocking flow throughcirculation channel 25. The movable member 30 includes an upper portion30a and a lower portion 30b forming a sleeve concentrically mounted withthe tubular member 15 exterior adjacent the channel 25. The portions 30aand 30b are secured together by engagement of thread portions 300 and30d, respectively. The inner surface of sleeve 30 forms a chamberdefined by a lower small diameter portion 30e, a first annular taperedshoulder 30f, a lower larger diameter portion 303, a locking recess3012, an upper larger diameter portion 301', a second annular taperedshoulder 30j, upper small diameter portion 30k, and

sealing surface 30m.

An enlarged outer portion 15a of the tubular member 15 extends into thechamber to serve as a stop and a guide for the sleeve 30. A taperedannular surface 15b located adjacent the circulation channel 25 limitsthe downward movement of the sleeve 30 by engaging shoulder 30j of thesleeve 30 in the closed position, as illustrated in FIGS. 4 and 5. Outersurface 15c of the enlarged portion 15a is located closely adjacentupper surface 30ito assist in guiding the sleeve 30 in the slidingmovement. The sleeve 30 further includes a flow port 30 therein having asmaller flow area than the channel 25 for permitting communicationthrough the sleeve 30 between the area adjacent the tubular member 15exterior surface adjacent the circulation channel 25 and the annulus l2exterior of the sleeve 30 when the sleeve is in the open position. Theflow port 31 is sealed from communicating'with the circulation channel25, blocking flow through the circulation channel 25, when the sleeve 30is in the closed position. The sleeve 30 is slidably sealed to theexterior of tubular member 15 at the upper end by apair of O-rings 30n.The sleeve 30 is also slidably sealed to the tubular member 15 adjacentportion 15a by a pair of O-rings 15d. The lower small diameter portion302 is slightly larger than the tubular member 15 forming an annularpassageway between the tubular member 15 and the 4 30f communicationwith theannulus 12 pressure when the shoulders 40b and 30f are engaged.

As illustrated in FIGS. 4, 5, 6, 7 and 8, a means for biasing movablemember 30 to the closed position is provided by spring 41. The spring ispositioned within the chamber between the sleeve 30 and the tubularmember and is retained in such position by retainer member 41 mountedwith tubular member 15 and the shoulder 40a of the sealing member 40.The engagement of the sleeve shoulder 30f by the sealing member shoulder40b acts as a carrying means carrying the sleeve 30'to the closedposition as the closing biasing of the spring 41 moves the slide 40 tothe lower positron.

A sensing channel 45 is formed through the wall of tubular member 15below the circulation channel for permitting communication from theinner bore 20 of the member 15 into a portion of the chamber above theshoulder 40a of the movable sealing member 40. The sealing member 40 ismaintained in the extended position, illustrated in FIG. 4, in responseto greater pressure in the inner bore 20 communicated through sensingchannel 45 to the shoulder 40a. This also maintains the sleeve in-theclosed position.

As illustrated in FIGS. 4, 5, 6, 7, 8 and 9, a means for locking thesleeve 30 in the open position includes a slidably movable ring shapedlatch member 50 positioned between the sleeve 30 and the tubular member15 and having a locking shoulder 50a and a stepped and partially taperedunlocking shoulder 50b. The latch member 50 is-movably mounted withrespect to both the tubular member 15 and the sleeve 30 between a loweror locking position and an upper or free position.

i The latch member 50 moves downward to the latch or portion. 30e forcommunicating the annular pressure 30 and the tubular member 15. Themember 40 is free to slidably move with respect to both the sleeve 30and the tubular member 15 between a lower or extended position,illustrated in FIG. 4, and an upper or retracted position, illustratedin FIGS. 5, 6, 7 and 8. The member 40 includes a first annular stepshoulder 40a and a second tapered annular shoulder 4012 adopted toengage shoulder 30f of the sleeve 30 for a purpose to be described morefully hereinafter. The slide 40 moves to the retracted position inresponse to the annulus pressure adjacent the tubular membercommunicated through the annular passageway between the tubular member15 and the portion 30e of the member 30 acting on the shoulder 40b ofthe member 40. A pair of 0- rings 15f seal an inner diameter surface 400of the slide 40 to the tubular member 15. Another pair of O-rings 40eseal an outer diameter surface 40d of sealing member 40 to the sleeve30. An O-ring 40d also seals the member 40 to the sleeve 30 when thetapered shoulder 40b engages shoulder 30f limiting the area of shoulderlocking position, illustrated in FIGS. 7 and 8 in response to increasedinner bore pressure urging on locking shoulder 50a and upward to thefree position, illustrated in FIGS. 4, 5 and 6, in response to increasedinner bore pressure urging on unlocking shoulder 50b. A pair of O-rings50c and 50d seal the latch member 50 to the tubular member 15 exteriorsurface and the surface 30i of the sleeve 30, respectively. Thefastening means furtherincludes a shear pin 51 for maintaining the latchmember 50 in the upper position and a split spring radially expansibledetent ring 52 positioned below the latch member 50. The detent 52 isadapted to move into the recess 30h of the sleeve 30 when the sleevemoves into the open position and is locked in the recess 30h by latchmember 50 moving downward within the radially expanded ring 52.

A locking channel 55 is formed through the wall of the tubular member 15at a location between the sensing channel 45 and-the circulation channel25 for permitting communicating from the inner bore 20 of the tubularmember 15 through the locking channel 55 into a-portion of the chamberabove the locking shoulder 50a of locking member 50'. Shoulder 50b ofthe latch member 50' is positioned in the chamber above the sensingchannel 45 for communicating with the inner bore 20 through the sensingchannel 45. The locking channel 55 and the sensing channel 45 areblocked from communicating in the chamber by the O-rings 40d and 50d.

A plug or means for controlling communication of pressure in the innerbore 20 to the desired portion of the valve is positioned in the innerbore 20 by lowereing or pumping the plug down the inner bore 20 of theproduction string T which will pass through the larger diameter innerbore 200 portion but will seat on and be retained by shoulder 20b belowthe circulation channel 25. The plug controls communication of surfacecontrolled increased inner bore pressure above the plug with the sensingchannel 45 and the locking channel 55 as desired. The use of a ball 60sealing the inner bore below the circulation channel is illustrated inFIG. 6 but a ball or slug sealing to and blocking the inner bore belowthe circulation channel 25 may be used. The plug 60 embodiment blockscommunication of the inner boreabove the plug with both the sensingchannel 45 and the locking channel 55 and is used in opening the valveas will be described more fully hereinafter.

Another embodiment of the plug or means for controlling communication ofpressure in the inner bore is a locking plug 61, illustrated in FIG. 7,having a shoulder 61a adapted to seat on shoulder 20b of the inner bore20 and positioning the plug 61 in the inner bore 20. An O-ring 61b sealsthe plug to the inner bore 200.

at a location between the locking channel 55 and the sensing channel 45permitting the inner bore 20 above the plug 61 to communicate with thelocking channel 55, but not permitting communication with the sensingchannel 45. An outer groove 61c and an annular manifold opening 61dadjacent the locking channel 55 permit communication between lockingchannel 55, the circulation channel 25 and the inner bore 21 of theproduction tubing T above the plug 61.'The sensing channel 45 is blockedby the plug 61 from communicating with the locking channel 55 andcirculation channel 25 in addition to the inner bore 21 of theproduction tubing T above the plug. The plug 61 also blockscommunication through the inner bore 20. A port 6le and blocking member61d assists in the removal of the plug 61, as is well known in the art.

An unlocking plug 62, illustrated in FIG. 8, is another embodiment ofthe plug or means for controlling communication of pressure in the innerbore 20 above the plug and is positioned in the inner bore 20 by theshoulder 62a seating on the shoulder 20b of the inner bore 20 when theplug 62 is lowered in the tubing T. Plug 62 is sealed to the inner bore200 between the circulation channel 25 and the'locking channel 55 byO-ring 62b and between the locking channel 55 and the sensing channel 45by O-ring 62c and again by O-ring 62d below the sensing channel 45. Theunlocking plug 62 permits communication between the inner bore 20 abovethe plug 62 and the sensing channel 45, but

blocks communication of the inner bore 20 above the plug with thelocking channel 55. Channel 62e permits communication between thesensing channel 45, the

circulation channel 25 and the inner bore 20 above the plug 62. Channel62f permits communication from the locking channel 55 to the inner bore20 below the sealing ring 62d of plug 62. Communication betweenftheinner bore 20 above the plug 62 to the inner bore 20 below the plug 62is also blocked.

In the use and operation of the present invention with the singlecompletion well, illustrated in FIG. 1, tubular member is connected inthe production tubing T immediately above the packer P for sealing offthe annulus 12 above the production zone and is lowered into the setperforated well casing 12 filled with drilling fluid as is well known inthe art. At the desired location the packer P is set sealing the annulus12 between the 6 v casing 11 and the production string T, as is wellknown in the art.

The valve 10 is assembled in the production tubing 10 in the conditionillustrated in FIG. 4. With equal pressure in the inner bore 20 and thearea immediately adjacent the exterior of the tool, the exteriorpressure provides equal and offsetting urging on the sleeve 30, whilethe inner bore pressure communicated through circulation channel 25andacting on shoulder 30jfor moving the sleeve 30 to the open position, isat least balancedv by the same inner bore'pressure communicated throughsensing channel 45 to the shoulder 40a of the movable sealing member 40.This allows the spring 41 to bias the sleeve to the closed position bythe slide 40 engaging shoulder 30f of the sleeve 30 and moving thesleeve 30 to the closed position as the slide 40 moves to the lowerposition. This position blocks all communication of the inner bore 20with the annulus 12 of the well through the valve. Should the pressurein the inner bore 20 become greater than the pressure immediatelyadjacent the exterior of the tool the greater pressure in the'inner bore20 will act on shoulder 40a to maintain the slide 40 in the lowerposition and thereby the sleeve 30 in the closed position. Asillustrated in FIG. 9, the bore 20 pressure responsive shoulder 40a and30] may be provided with different size areas on which the pressureurges. By-making the shoulder 40a larger than the shoulder 30j pressurein the bore 20 will'urge the valve closed. In this manner the valve maybe pumped closed should the spring 41 malfunctionor break.

Lowering the production tubing T into the well casing 11 fills the innerbores 21 and 20 with drilling fluid through the tubing T open lower endand should cause the pressure in the annulus l2-to become greater thanthe pressure in the inner bore 20 because of the difference in heightsof columns of drilling fluid. The greater pressure inthe annulus 12 willmaintain the sleeve 30 in the closed position, but the slide member 40will move to the upper position illustrated in FIG. 5. The movablesealing member 40 has the greater pressure in the annulus 12 actingupwardly on the shoulder 40b while the pressure in the inner bore 20 isacting downwardly on shoulder 40a. Since the effective surface area ofshoulders 40a and 40b on which these pressures act are equal, the slidemember 40 will move upward. The upward movement of the movable sealingmember 40 to a position spaced from the shoulder 30f permits the greaterpressure in the annulus 12 to act on the entire shoulder 30f as a meansfor maintaining the sleeve 30 in the closed position in response to thegreater pressure in the annulus 12. This also occurs in the embodimentillustrate in FIG. 9.

To complete the well permitting flow of hydrocarbons from the formationF, it is necessary to displace the heavy drilling fluid from the bore 21of the production string T with a lower density fluid, as is well known7 in the art. As illustrated in FIG. 6, the plug or ball is well knownin the art. The increased pressure above the plug 60 is communicatedthrough the circulation channel 25 to the shoulder 30e where it urges onthe shoulder 30e to overcome the pressure in the annulus 12 urging onshoulder 30for the urging of the movable slide 40 and moves the sleeve30 to the open position. This allows the heavy drilling fluid within theinner bore 20 of the production string T above the plug 60 to flowthrough the circulation channel 25 and the flow port 31 into the annulus12 of the well above the packer P. The drilling fluid in the annulus 12is removed from the well casing 11 at the surface permitting theproduction string to fill with lighter fluid. When the production stringT above the plug 60 is filled with lower density fluid above theblocking means 60, the pumps are stopped decreasing the pressure intheinner bore 20 above the ball or plug 60. When the pressure in the innerbore 20 decreases sufficiently to be substantially equal to the pressurein the annulus 12, the spring 41 closes the valve blocking flow from theinner bore 20 into the annulus 12. With the valve now closed, formationF pressure greater than the hydrostatic pressure within the well casing11 at the perforations allows the hydrocarbons to flow into the casing11 through the perforations O and on to the surface through the innerbore 21 of the production tubing T, as is well known in the art.Normally the blocking means 60 is retrieved by the formation pressureflowing the ball 60 to the surface where it is removed from the bore 21completing the well. The ball 60 may be removed by smashing the ball 60or by retrieving with a wire line, but the removal by formation pressurewith retrieval at the surface is preferred.

To kill the single production zone well by filling the inner bore 21 ofthe production tubing T with a heavy fluid, the locking plug 61 islowered down the production tubing inner bore 21 until it seats onshoulder b of the tubular member 10. The plug 61 communicates the innerbore 20 above the plug 61 with the circulation channel 25 and thelocking channel 55 while blocking communication past the plug 61.Surface pumps are then used to increase the pressure in the inner bore21 of the production string T above the plug 61. This increased pressureis communicated to the inner bore 20 above the plug 61 and communicatedthrough the circulation channel 25 to the shoulder e for moving thesleeve 30 to the open position. The pressure in the inner bore 20 abovethe plug 61 is also communicated by the plug 61 through locking channel55 to the locking shoulder 50a of the latch member 50. The increasedpressure acting on shoulder 50a moves the latch member 50 downward,shearing pin 51, and moving the latch member 50 to the lower position,illustrated in FIGS. 7 and 8. in this position, the step shoulder 50bmoves within the detent 52 locking it in the recess 30h of the sleeve 30and thereby mechanically locking the sleeve 30 in the open position. Thelatch member 50b prevents the detent 52 from moving out of the recess3011 which would allow the valve to close. With the valve nowmechanically locked open, the pumps are stopped. The surface pumps arethen connected to the well casing 11 and are used to inject or introducethe heavier drilling fluid into the annulus 12 above the packer P. Theheavier drilling fluid in the annulus 12 then back circulates from theannulus 12 above the packer P through flow port 31 and circulationchannel 25 into the inner bore 20 above the plug 61 filling the innerbore 21 of the production tubing T. The lighter fluids displaced by theheavier drilling fluid are removed from the inner bore 21 of theproduction tubing T at the surface. The heavier drilling fluid in theinner bore 21 establishes a greater hydrostatic head preventing flow ofhydrocarbons from the formation through the perforations O in the casing11 killing the well. Plug 61 may be removed at the surface when thetubing is pulled or retrieved by a wire line when the back circulationis complete and formation pressure is no longer within the tubing Tinner bore 21.

To recomplete a single production zone killed well having a locked opensleeve valve, the locking plug 61 is removed and the cross over plug 62is lowered down the inner bore 21 of production tubing T until it seatson shoulder 20b. The crossover plug 62 positioned in the inner bore 20by shoulder 20b permits communications of the inner bore above the plug62 with sensing channel 45 and the circulation channel 25. The lockingchannel communicates with the inner bore 20 below the blocking plug 62,but is blocked from communicating with the inner bore above the plug 62.The plug 62 also blocks communication through the inner bore 20. Thesurface pumps are used to inject the light fluid into the inner bore 21of the production tubing T. This in- I creases the inner bore 20pressure above the plug 62 in the open valve 10 and displaces the heavydrilling fluid below the lighter fluid through the circulation channel25 and the flow port 31 into the annulus 12 of the well above the packerP and back to the surface where it is removed from the casing 11. Theincreased pressure in the inner bore 20 is also communicated throughplug channel 62c and the sensing channel 45 to shoulder 50b of the latchmember 50 for moving the latch 50 upward away. from the detent 52unlocking the sleeve 30 and freeing sleeve 30 to be moved to the closedposition by the spring 41. Fluid on the upper side 50a of latch member50 is vented into the inner bore 20 below the plug 62 by channel 62fpreventing-any trapped fluid from blocking movement of the latch member50 to the upper position. Light fluid is pumped into the inner bore 21until it fills all of the inner bore 21 above the plug 62. The pressurein the inner bore 21 is then decreased closing the valve 10. When theplug 62 is retrieved the hydrocarbons are free to flow into the casing12 through the perforation O and on to the surface through the innerbore 21 of production tubing T as is well known in the art.

FIG. 2 illustrates use of the present invention in a dual completionwell. The completion and kill valve 10 is placed in the lower zoneproduction tubing T immediately above the packer P-l separating theupper and lower production zones. To complete the dual completion well,the plug is lowered down'the inner bore 21 of the lower production zonetubing string T until it seats on the shoulder 20b in the inner bore 20of the valve 10. Surface pumps are then used to inject or introduce alighter density fluid into the production tubing inner bore 21 above theball 60 while also increasing the pressure in the inner bore 20 abovethe ball 60 to open the valve 10. The displaced heavier drilling fluidis removed from the well at the surface through the inner bore 21 of theupper zone production tubing T-l. The lighter fluid is circulated fromthe inner bore 21 of the production tubing T through the circulationchannel 25 into the upper production zone 12a, and through the innerbore 21 of the upper zone production tubing T-1 to the surface. Thepumps continue to introduce the light fluid until the inner bore 210ithe upper zone production tubing T is filled with lighter density fluidfrom the lower zone production tubing inner bore. When the inner bore 21of both tubings T and T-l are filled with the light fluid, the pumps areshut down, lowereing the pressure in the inner bore 20 above'the plug 60and allowing the spring 41 to move the sleeve 30 to the closed position.The pressure in the upper formation' is then free to flow hydrocarbonsthrough perforations O in casing 11 into the area 12a and on to thesurface through the inner bore of production tubing T1. The plug or ball60 must be removed from the valve before the production tubing T canflow the lower formation hydrocarbons to the surface.

Use of thevalve- 10 in the killing of a dual completed well by fillingthe inner bore 21 of both production tubings T and T-l with a heavierfluid may be accomplished by two methods. In the first method, the stepof the method of completing the dual zone well are repeated with twoexceptions. The plug 60 lowered in the inner bore 21 of the productiontubing T need not be removed to kill the well. The other change is thata heavy fluid is injected into the inner bore 21 of the lower zonetubing above the .plug 60 and allowed to circulate through the valve 10into the inner bore 21 of the upper zone production tubing T-1 andfilling both inner bores 21 with the heavy fluid while the lighter fluidis removed from the inner bore 21 of the upper zone production tubing.

In the second method to kill a dual completion well, the locking plug 61is lowered down the inner bore 21 of the lower zone production tubing Tto seat in the valve 10. The pressure in the inner bore'2l above theplug 62 is then increased to open and mechanically lock open the valve10. Heavy drilling fluid is then injected into the inner bore 21 of theupper zone production tubing T-1 while removing thedisplaced lighterfluid from the inner bore 21 of the lower zone production tubing abovethe sleeve valve 10. The injection of -the heavy drilling fluid iscontinued untilthe inner at increased pressure into the inner bore 21 ofthe middle zone production tubing T-l above the plug 60. This opens thevalve 10b and permits flow of fluid from the inner bore 21 of the middlezone production tubing T-l into the annulus 12b between packers P-2 andP-3 and up the inner bore 21 of the upper zone production string T-2 tothe surface. The heavy fluid within the well is removed through theinner bore 21 of the upper zone production tubing T-2. When the lighterfluid is circulating back to the surface through the upper zoneproduction tubing T-2, the pumps are shut down decreasing the'pressurein the inner bore of the middle zone production tubing T-l, closing thevalve 1012. When the plugs 60 are removed, all three zones are ready toproduce and the well is completed.

To kill the triple producing zone well, a plug 60 is lowered down theinner bore 21 of the lower zone production tubing T until it seats onthe shoulder within the inner bore of valve 10a. The surface pumps arethen used to introduce'heavy drilling fluid at increased pressure intothe inner bore 21 of the produc- T-l with heavy drillingfluid. To killthe upper producbores of both the upper and lower zone productiontubings are filled with heavy drilling fluid therebykilling the well. I

FIG. 3 illustrates the use of the present invention in completing athree zone production well by displacing the heavy fluid in the innerbores of the production tubings. A packer P-l separates the lower zonefrom the middle zone while-a packer P-2 separates the middle zone andthe upper zone. The packer P-3 seals the annulus 12 above the upperzone. The bottom two zones are first completed by lowering the plug 60in the inner bore 21 of the lower zone production tubing to seat in theinner bore of valve 10a and then injecting lighter fluid in the innerbore 21 of the lower zone production tubing T to increase the pressureabove the plug 60 to thereby open the valve 10a. The displaced heavydrilling fluid is removed from the well through the inner bore 21 of themiddle zone production tubing T-1. The injection of the lighter fluidabove the plug 60 contin- -ues until the inner bore 21 of the middlezone production tubing T-l is filled with the lighter fluid. The pumpsare shut down decreasing the pressure in the inner bore 21 of the lowerzone production tubing closing valve 10a. A plug 60 is then lowered downthe inner bore 21 of the middle zone production tubing T-l until itseats in the valve 10b. Lighter fluid is then injected tion zone, theplug 60 is lowered down the production tubing T-l until it seats on theshoulder 20b of valve 10b. Surface pumps are then used to introduceheavy drilling fluid into the inner bore 21 of the production tubing T-1at increased pressure.'The increased pressure in the inner bore 20 ofthe middle zone production tubing T-l above the plug 60 opens the valve10b circulating the heavier drilling fluid into the annulus 12b andbackto the surface through the inner bore 21 of the upper zoneproduction tubing T-2. The displaced lighter fluid is removed from thewell through the inner bore 21 of the upper zone production tubing T-2.Filling the inner bore 21 of the upper zone production tubing T-Z withthe heavy fluid kills the upper zone and completes the killing of thewell. I

From the multiple zonemethods set out above it si apparent that aplurality of the valves 10 connected in the production tubings may beused to complete and kill awell having any number of production strings.If a plurality of N completion and kill valves 10 are employed, a wellhaving a plurality of N 1 production strings, may be completed andkilled by circulating different density fluids in the well through thevalves 10.

The foregoing disclosure and description of the inventionareillustrative and explanatory thereof, and various changes in thesize, shape and materials as well as in the details of the illustratedconstruction may be made without departing from the spirit of theinvention.

What is claimed is: V

1. A process for completing a single production zone in a well having aset well casing and production tubing inner bore filled with heavydrilling fluid by displacing the heavy drilling fluid from theproduction tubing inner borethrough a pressure responsivesleeve valvelocated in the production tubing above a packer with a lighter densityfluid comprising:

a. lowering a plug down the inner bore of the production string;

b. seating the plug in the sleeve valve;

c. injecting a lighter density fluid into the inner bore of theproduction tubing above the plug;

01. increasing the pressure of the fluid in the production tubing innerbore above the plug for opening the sleeve valve;

e. removing the displaced heavier drilling fluid from the well casing;

f. substantially filling the inner bore of the production tubing abovethe plug with the lighter density fluid;

g. decreasing the pressure of the fluid in the inner bore of theproduction tubing above the plug for closing the sleeve valve;

h. removing the plug from the sleeve valve wherein the well iscompleted.

2. A process for completing two production zones in a well having a setwell casing, an upper zone and a lower zone production tubing havinginner bores filled with heavy drilling fluid by displacing the heavydrilling fluid from the upper zone and lower zone production tubinginner bores with a lighter density fluid through the use of a pressureresponsive sleeve valve located in the lower zone production tubingabove a packer separating the production zones comprising:

a. lowering a plug down the inner bore of the lower zone productionstring;

b. seating theplug in the sleeve valve;

c. injecting a lighter density fluid into the inner bore of the lowerzone production tubing above the plug;

d. increasing the pressure of the fluid in the lower zone productiontubing inner bore above the plug for opening the sleeve valve;

e. removing the displaced heavier drilling fluid from the well throughthe upper zone production tubing inner bore;

f. substantially filling the upper zone production tubing inner borewith lighter density fluid from the lower zone production tubing innerbore;

g. decreasing the pressure of the fluid in the inner bore of the lowerzone production tubing above the plug for closing the sleeve valves; and

h. removing the plug from the sleeve valve wherein both' zones of thewell are completed.

3. A process for completing three production zones in a well having aset well casing, an upper, a middle and a lower production zone tubinginner bore filled with heavy drilling fluid by displacing the heavydrilling fluid with a lighter density fluid from the production tubinginner bores through the use of a pressure responsive sleeve valvelocated in the lower zone production tubing above a packer separatingthe lower zone and the middle zone and a second pressure responsivesleeve valve located in the middle zone production tubing above a packerseparating the lower zone and the middle zone comprising:

a. lowering a plug down the inner bore of the lower zone productionstring;

b. seating the plug in the lower zone production string sleeve valve;

c. injecting a lighter density fluid into the inner bore 6 of the lowerzone production tubing above the plug;

12 d. increasing the'pressure of the fluid in the lower zone productiontubing inner bore above the plug for opening the sleeve valve located inthe lower zone production tubing;

e. removing the displaced heavier drilling fluid from the well throughthe middle zone production tubing inner bore;

f. partially filling the middle zone production tubing inner bore abovethe middle zone production tubing sleeve valve with lighter densityfluid from the lower zone production tubing inner bore;

g. decreasing the pressure of the fluid in the lower zone productiontubing inner bore above the plug for closing the sleeve valve in thelower zone production tubing;

h. lowering a plug down the inner bore of the middle zone productionstring;

i. seating the plug in the middle zone production string sleeve valve;

j. injecting a lighter density fluid into the inner bore of the middlezone production tubing above the P g;

k. increasing the pressure of the fluid in the middle zone productiontubing above the plug for opening the sleeve valve;

. removing the displaced heavier drilling fluid from the well throughthe upper zone production tubing inner bore;

m. substantially filling the upper zone production tubing inner borewith lighter density fluid from the middle zone production tubing innerbore;

n. decreasing the pressure of the fluid in the middle zone productiontubing inner bore above the plug for closing the valve; and

' o. removing the plugs from the middle zone and lower zone productiontubing inner bores wherein the well is completed.

4. A process for recompleting a production zone of a well previouslykilled by locking open a pressure responsive sleeve valve located in aproduction tubing above a packer and back circulating heavy fluid down awellcasing, through the locked open sleeve valve to fill the productiontubing inner bore by displacing the heavy fluid in the production tubinginner bore with a lighter density fluid and'unlocking the locked opensleeve valve permitting it to close comprising:

a. lowering-a plug down the inner bore of the production string;

b. seating the plug in the sleeve valve;

c. injecting a lighter density fluid into the inner bore of theproduction tubing above the plug;

d. increasing the pressure of the fluid in the production tubing innerbore above the plug for unlocking the valve and maintaining the valveopen;

e. removing the displaced heavier fluid from the well casing;

f. substantially filling the inner bore of the production tubing withthe lighter density fluid;

g. decreasing the pressure of the fluid in the inner 5. A process ofcompleting a well by displacing a heavy fluid within a bore of aproduction tubing with a lighter fluid using a controllable valvemounted with the production tubing for forming a flow enabling circ.injecting the lighter fluid into the well to displace the heavy fluidwith the lighter fluid wherein the well is completed.

6. The invention as set forth in claim 5, including the step of:

removing the displaced heavier fluid from the bore of the productiontubing through the circulation channel to complete the well.

7. The method as set forth in claim 5, including the step of:

substantially filling the bore of the production tubing with the lighterfluid to complete the well.

8. The method as set forth in claim 5, including the step of:

decreasing the pressure of the fluid in the bore of the productiontubing after injecting the lighter fluid for closing the circulationchannel wherein the well is completed.

9. The method as set forth in claim 5, including the injecting thelighter fluid into the bore of the production tubing to displace theheavier fluid.

10. The method as set forth in claim 5, including the step of:

locking open the circulation channel to enable communication through theproduction tubing when the controlled fluid pressure is reduced.

11. The method as set forth in claim 10, including the step of:

injecting the lighter fluid into the bore of the production tubingthrough .the circulation channel wherein the well is completed. 12. Themethod as set forth in claim 11, including the step of: v i

flowing the lighter fluid through a well casing to a location adjacentthe circulation channel for injecting into the bore of the productiontubing through the circulation channel. 13. The method as set forth inclaim 11, including the stepof:

flowing the lighter fluid through a bore of a second production tubingpositionedin the well to a location adjacent the circulation channel forinjecting into the bore of the production tubing through the circulationchannel. 14. The method as set forth in claim 10, including the step of:

unlocking the circulation channel to thereafter block communicationthrough the circulation channel when the controlled fluid pressure isreduced.

15. A process for completing a well having a production tubing with abore filled with heavy fluid by displacing the heavy fluid from theproduction tubing bore with a lighter density fluid by using a pressureresponsive valve connected in the production tubing above a packer forproviding a circulation flow channel through the production tubing whenfluid pressure is applied in a controlled manner to the valvecomprising:

a. seating a plug in the valve by lowering the plug down the bore of theproduction string to control the application of fluid pressure to thevalve.

b. increasing the pressure of the fluid in the production tubing boreabove the plug for controlled application to the valve for opening thevalve to provide the circulation flow channel;

c. displacing substantially the heavier fluid from the bore of theproduction tubing with the lighter fluid; and

d. removing the plug from the valve wherein the well is completed.

16. The method as set forth in claim 15, including the step of:

removing the displaced heavier fluid from the bore of the productiontubing by flowing through the circulation channel provided by the valve'to complete the well.

17. The method as set forth in claim 15, including the step of:

substantially filling the bore of the production tubing with the lighterfluid to complete the well.

l8. The method as set forth in claim 15, including the step of:

decreasing the pressure of the fluid in the bore of the productiontubing after injecting the lighter fluid for closing the valve to blockflow through the circulation channel wherein the well is completed.

19. The method as set forth in claim 15, including the step of:injectin'g'the lighter fluid into the bore of the production tubing todisplace the heavier fluid.

20. Themethod'as set forth in claim 15, including the step of: 7

locking the valve in the open condition providing the circulationchannel by applying controlled fluid pressure to the valve to enablecommunication through the production tubing when the controlled fluidpressure is reduced.

21. The method as set forth in claim 15, including the step of:

injecting the lighter fluid into the bore of the production tubingthrough the circulation channel wherein the well is completed.

22. The method as set forth in claim 21, including the I step of:

flowing the lighter fluid through a well casing to a location adjacentthe valvefor injecting into the bore of the production tubing throughthe circulation channel. 23. The method as set forth in claim 21,including the step of:

flowing the lighter fluid through a bore of a second production tubingpositioned in the well to a loca-- tion adjacent the valve for'injectinginto the bore of the first production tubing through the circulationchannel. 24. The method as set forth in claim 20, including the step of:

unlocking the valve by applying controlled fluid pres-- sure to thevalve to thereafter block communication through the circulation channelwhen the applied controlled fluid pressure is reduced.

1. A process for completing a single production zone in a well having aset well casing and production tubing inner bore filled with heavydrilling fluid by displacing the heavy drilling fluid from theproduction tubing inner Bore through a pressure responsive sleeve valvelocated in the production tubing above a packer with a lighter densityfluid comprising: a. lowering a plug down the inner bore of theproduction string; b. seating the plug in the sleeve valve; c. injectinga lighter density fluid into the inner bore of the production tubingabove the plug; d. increasing the pressure of the fluid in theproduction tubing inner bore above the plug for opening the sleevevalve; e. removing the displaced heavier drilling fluid from the wellcasing; f. substantially filling the inner bore of the production tubingabove the plug with the lighter density fluid; g. decreasing thepressure of the fluid in the inner bore of the production tubing abovethe plug for closing the sleeve valve; h. removing the plug from thesleeve valve wherein the well is completed.
 2. A process for completingtwo production zones in a well having a set well casing, an upper zoneand a lower zone production tubing having inner bores filled with heavydrilling fluid by displacing the heavy drilling fluid from the upperzone and lower zone production tubing inner bores with a lighter densityfluid through the use of a pressure responsive sleeve valve located inthe lower zone production tubing above a packer separating theproduction zones comprising: a. lowering a plug down the inner bore ofthe lower zone production string; b. seating the plug in the sleevevalve; c. injecting a lighter density fluid into the inner bore of thelower zone production tubing above the plug; d. increasing the pressureof the fluid in the lower zone production tubing inner bore above theplug for opening the sleeve valve; e. removing the displaced heavierdrilling fluid from the well through the upper zone production tubinginner bore; f. substantially filling the upper zone production tubinginner bore with lighter density fluid from the lower zone productiontubing inner bore; g. decreasing the pressure of the fluid in the innerbore of the lower zone production tubing above the plug for closing thesleeve valves; and h. removing the plug from the sleeve valve whereinboth zones of the well are completed.
 3. A process for completing threeproduction zones in a well having a set well casing, an upper, a middleand a lower production zone tubing inner bore filled with heavy drillingfluid by displacing the heavy drilling fluid with a lighter densityfluid from the production tubing inner bores through the use of apressure responsive sleeve valve located in the lower zone productiontubing above a packer separating the lower zone and the middle zone anda second pressure responsive sleeve valve located in the middle zoneproduction tubing above a packer separating the lower zone and themiddle zone comprising: a. lowering a plug down the inner bore of thelower zone production string; b. seating the plug in the lower zoneproduction string sleeve valve; c. injecting a lighter density fluidinto the inner bore of the lower zone production tubing above the plug;d. increasing the pressure of the fluid in the lower zone productiontubing inner bore above the plug for opening the sleeve valve located inthe lower zone production tubing; e. removing the displaced heavierdrilling fluid from the well through the middle zone production tubinginner bore; f. partially filling the middle zone production tubing innerbore above the middle zone production tubing sleeve valve with lighterdensity fluid from the lower zone production tubing inner bore; g.decreasing the pressure of the fluid in the lower zone production tubinginner bore above the plug for closing the sleeve valve in the lower zoneproduction tubing; h. lowering a plug down the inner bore of the middlezone production string; i. seating the plug in the middle zoneproduction string sleeve valve; j. injecting a lighter density fluidinto the inner bore of thE middle zone production tubing above the plug;k. increasing the pressure of the fluid in the middle zone productiontubing above the plug for opening the sleeve valve; l. removing thedisplaced heavier drilling fluid from the well through the upper zoneproduction tubing inner bore; m. substantially filling the upper zoneproduction tubing inner bore with lighter density fluid from the middlezone production tubing inner bore; n. decreasing the pressure of thefluid in the middle zone production tubing inner bore above the plug forclosing the valve; and o. removing the plugs from the middle zone andlower zone production tubing inner bores wherein the well is completed.4. A process for recompleting a production zone of a well previouslykilled by locking open a pressure responsive sleeve valve located in aproduction tubing above a packer and back circulating heavy fluid down awell casing, through the locked open sleeve valve to fill the productiontubing inner bore by displacing the heavy fluid in the production tubinginner bore with a lighter density fluid and unlocking the locked opensleeve valve permitting it to close comprising: a. lowering a plug downthe inner bore of the production string; b. seating the plug in thesleeve valve; c. injecting a lighter density fluid into the inner boreof the production tubing above the plug; d. increasing the pressure ofthe fluid in the production tubing inner bore above the plug forunlocking the valve and maintaining the valve open; e. removing thedisplaced heavier fluid from the well casing; f. substantially fillingthe inner bore of the production tubing with the lighter density fluid;g. decreasing the pressure of the fluid in the inner bore of theproduction tubing above the plug for closing the valve; and h. removingthe plug from the sleeve wherein the well is recompleted.
 5. A processof completing a well by displacing a heavy fluid within a bore of aproduction tubing with a lighter fluid using a controllable valvemounted with the production tubing for forming a flow enablingcirculation channel through the production tubing, including the stepsof: a. positioning a plug in the bore of the production tubing; b.controlling the application to the valve of fluid pressure in the boreof the production tubing with the plug to establish the circulationchannel for communicating through the production tubing; and c.injecting the lighter fluid into the well to displace the heavy fluidwith the lighter fluid wherein the well is completed.
 6. The inventionas set forth in claim 5, including the step of: removing the displacedheavier fluid from the bore of the production tubing through thecirculation channel to complete the well.
 7. The method as set forth inclaim 5, including the step of: substantially filling the bore of theproduction tubing with the lighter fluid to complete the well.
 8. Themethod as set forth in claim 5, including the step of: decreasing thepressure of the fluid in the bore of the production tubing afterinjecting the lighter fluid for closing the circulation channel whereinthe well is completed.
 9. The method as set forth in claim 5, includingthe step of: injecting the lighter fluid into the bore of the productiontubing to displace the heavier fluid.
 10. The method as set forth inclaim 5, including the step of: locking open the circulation channel toenable communication through the production tubing when the controlledfluid pressure is reduced.
 11. The method as set forth in claim 10,including the step of: injecting the lighter fluid into the bore of theproduction tubing through the circulation channel wherein the well iscompleted.
 12. The method as set forth in claim 11, including the stepof: flowing the lighter fluid through a well casing to a locationadjacent the circulation channel for injecting into the bore of theproduction tubing through the circulation channel.
 13. The method as setforth in claim 11, including the step of: flowing the lighter fluidthrough a bore of a second production tubing positioned in the well to alocation adjacent the circulation channel for injecting into the bore ofthe production tubing through the circulation channel.
 14. The method asset forth in claim 10, including the step of: unlocking the circulationchannel to thereafter block communication through the circulationchannel when the controlled fluid pressure is reduced.
 15. A process forcompleting a well having a production tubing with a bore filled withheavy fluid by displacing the heavy fluid from the production tubingbore with a lighter density fluid by using a pressure responsive valveconnected in the production tubing above a packer for providing acirculation flow channel through the production tubing when fluidpressure is applied in a controlled manner to the valve comprising: a.seating a plug in the valve by lowering the plug down the bore of theproduction string to control the application of fluid pressure to thevalve. b. increasing the pressure of the fluid in the production tubingbore above the plug for controlled application to the valve for openingthe valve to provide the circulation flow channel; c. displacingsubstantially the heavier fluid from the bore of the production tubingwith the lighter fluid; and d. removing the plug from the valve whereinthe well is completed.
 16. The method as set forth in claim 15,including the step of: removing the displaced heavier fluid from thebore of the production tubing by flowing through the circulation channelprovided by the valve to complete the well.
 17. The method as set forthin claim 15, including the step of: substantially filling the bore ofthe production tubing with the lighter fluid to complete the well. 18.The method as set forth in claim 15, including the step of: decreasingthe pressure of the fluid in the bore of the production tubing afterinjecting the lighter fluid for closing the valve to block flow throughthe circulation channel wherein the well is completed.
 19. The method asset forth in claim 15, including the step of: injecting the lighterfluid into the bore of the production tubing to displace the heavierfluid.
 20. The method as set forth in claim 15, including the step of:locking the valve in the open condition providing the circulationchannel by applying controlled fluid pressure to the valve to enablecommunication through the production tubing when the controlled fluidpressure is reduced.
 21. The method as set forth in claim 15, includingthe step of: injecting the lighter fluid into the bore of the productiontubing through the circulation channel wherein the well is completed.22. The method as set forth in claim 21, including the step of: flowingthe lighter fluid through a well casing to a location adjacent the valvefor injecting into the bore of the production tubing through thecirculation channel.
 23. The method as set forth in claim 21, includingthe step of: flowing the lighter fluid through a bore of a secondproduction tubing positioned in the well to a location adjacent thevalve for injecting into the bore of the first production tubing throughthe circulation channel.
 24. The method as set forth in claim 20,including the step of: unlocking the valve by applying controlled fluidpressure to the valve to thereafter block communication through thecirculation channel when the applied controlled fluid pressure isreduced.